As the digital-water.city project enters its final months, what have our DWC partners in Sofia been up to?  

Our partners in Sofia have been busy testing the online and offline low-cost temperature sensors, used to detect overflows in the sewer system. Eight out of the ten offline sensors installed in November 2020, have been working well and are collecting data.  

With regards to the online sensors installed in August 2021, the data transmission of some devices didn’t work as well as expected. However, the ICRA is testing the sensors to fix this issue in collaboration with the local team. Overall, there are eight online devices that work well and five more that were just installed in May 2022.  

The online platform created by IoTsens has been a  success in Sofia. The rainfall data collected is sent  to the platform both when it is in online and offline mode. Integrating the rain gauge data into the online platform was one of the main challenges, and we are pleased to see that this has come to fruition.  

After a training on March 2021, the partners in Sofia performed 2,5 km of sewer cleaning (out of the 10km targeted) and inspected the sewers with XPECTION (a video nozzle). Thanks to this first trial, they were able to evaluate this new technique and share their experience with the partners in Berlin.  

In Sofia, the cleaning of the sewers would be traditionally done by a team and a cleaning truck. With the video nozzle, an expert supervisor for the team had to be found and more people will be needed in the video team to help them reach their targets.  

The lesson learned in 2021 for our Sofia partners is that not all trials are successful the first time, but they are a great way to learn from mistakes.  

By 2022, they hope to reach the target number of devices installed and the sewer cleaning target of 10km.  

We wish them all good luck and congratulate them on their hard work!